Small transmitters with high efficiency power amplifiers are especially susceptible to performance degradation if the impedance of the antenna is perturbed, for example by the presence of nearby objects or ice forming on the antenna. Such an impedance mismatch can be resolved by adding a tunable impedance matching network between the amplifier and the antenna. Conventional circuitry for measuring the antenna detuning and adjusting the matching network, however, typically requires additional space, and adds loss to the transmission path from the transmitter to the antenna. Further, such circuitry typically requires that both the power amplifier and the antenna each be nominally matched to a common real impedance (e.g., 50Ω).